Weather at the winter and stopover areas determines spring migration onset, progress, and advancements in Afro-Palearctic migrant birds

Significance Migratory birds show alarming declines across the globe, especially birds that migrate over long distances. A limited ability to adjust spring arrival to climate change at the breeding grounds, especially compared to residents and shorter-distance migrants, is thought to be a major cause. Our results show that breeding area arrival of cross-continental migrant birds is nevertheless, similarly to short-distance migrants, largely driven by weather conditions at the wintering and stopover grounds. Additionally, our study indicates that not only temperature rise but also more favorable wind conditions have allowed birds to arrive earlier. A better understanding of climate change influences on the timing of biological phenomena is vital to understanding and ultimately battling the consequences of climate change on population demographics.